The cutterhead is mounted at the free end of a drive shaft which transfers the drive torque of a motor such as an internal combustion engine to the cutterhead. The cutterhead includes a pot-shaped housing having a housing hub extending toward the open end of the housing. The housing is held on the end portion of the drive shaft via the housing hub and is driven in rotation by the drive shaft. The housing includes a spool having a hub which is held on the housing hub coaxially to the drive shaft. A cutting filament is wound on the spool and has an end which extends into free space through an exit opening in a peripheral wall of the housing. The peripheral wall axially overlaps the spool. The cutting end of the cutting filament is radially accelerated about the rotating cutterhead during the operation of the brushcutter and cuts the plant matter in the vicinity of the cutterhead.
U.S. Pat. No. 5,671,536 discloses a cutterhead having a spool wherein two spool chambers are formed on the periphery in the spool by a radial partition wall. Cutting filaments are wound in each of the spool chambers. Each cutting end extending into free space is assigned an exit opening in the housing. The partition wall of the spool lies approximately at the same axial elevation as the exit opening and is provided with a lead-in channel through which the other filament end is guided into the interior of the spool and is there held friction tight. The winding up of the cutting filament on the spool should be possible without disassembly of the spool from the housing in that the end portion of the filament is guided through the lead-in channel through the interior of the spool. The lead-in channel is configured in the spool and opens into free space at the outer end face of the spool which is at the open end of the pot-shaped housing. The filament end which exits here should be bent over and inserted into an opening provided next to the channel opening in the end face of the spool. The replacement cutting filament is wound up after the insertion of the end by manual rotation of the spool chamber. An eccentric strut is formed at the exposed end face of the spool which is intended to facilitate the wind-up operation for the operator. The wound up cutting filament is held in a friction-tight manner and the remaining end is flung from the lead-in channel as a consequence of centrifugal forces when the complete length of filament is unwound.
The entrance of the lead-in channel in the partition wall overlaps, with its cross section, the entire exit opening in the housing to ensure that the replacement filament reaches the lead-in channel from the outside after being pushed through the exit opening. The lead-in channel defines a rise in at least one of the spool chambers on which the filament is wound. For the proper transport and discharge of the filament from the cutterhead, a uniformly arranged wind-up in the spool chambers is necessary in order to avoid an otherwise possible clamping of the filament layers lying disordered one next to the other. The known configuration of the lead-in channel, however, causes an asymmetry in the spool chambers which can lead to a nonuniform winding up of the filament. The inlet cross section of the lead-in channel is considerably larger than the diameter of the filament so that the replacement filament passes through the entrance cross section at any desired location in advance of winding up on the spool. For this reason, it cannot be precluded that the filament reaches the incorrect spool chamber at the start of the wind-up operation in which incorrect spool chamber an already wound up filament could possibly be disposed. Increased attention of the operator and additional manipulation of the filament and the cutterhead are required in order to allocate the filament to be wound to the appropriate spool chamber. In this way, the filament can be directed into the spool in the required direction.